Mother-child transmission of mutans streptococci

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Mother-child transmission of mutans streptococci
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The window of infectivity for mutans streptococci
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The earlier the mutans streptococci are
colonized, the higher is the risk for caries
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Transmission of mutans streptococci

• The mother (infecting person) has high salivary
  mutans streptococci counts
• Several daily saliva contacts between the child
  and the mother must take place

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Methods to prevent the acquisition of mutans
streptococci

• Information on mother-child transmission of ms,
  advice on diet and oral hygiene
• Chemical methods (chlorhexidine)
• Xylitol

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Mother-child study

• Eva Söderling and Pauli Isokangas
• Institute of Dentistry, Turku
• Ylivieska Health Centre, Ylivieska

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Subjects

• At baseline 195 mothers with high salivary mutans
  streptococci counts (60 of all mothers)
• 2-year examination 169 mother-child pairs
• 6-year examination 147 children

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Study groups

• Xylitol group xylitol chewing gum 4 times a day
• Fluoride (F control) group fluoride varnish
  (2.26) treatments 2 times a year
• Chlorhexidine (CHX) group CHX varnish (40)
  treatments 2 times a year
• All interventions discontinued when the child
  was 2 years old

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Xylitol chewing gum
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Only the mothers used xylitol/were treated with
varnish no additional treatments to children
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Results
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Mutans streptococci of the mothers

• High salivary mutans streptococci counts in all
  groups throughout the study
• No differences between the study groups

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Mutans streptococci of the 2-year-old children
(Söderling et al., JDR 2000)

• The childs risk of having mutans streptococci
  colonization in the dentition was 5-fold in the F
  group and 3-fold in the CHX group as compared to
  the Xylitol group

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Caries occurence in children

• At the age of 5 years the need of restorative
  treatment was 71-75 lower in the Xylitol group
  as compared to the F and CHX groups
• The occurence of caries and early mutans
  streptococci colonization were in agreement

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Prevention of Maternal-Infant Transmission of
Caries

• A Randomized Clinical Trial

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Investigator Affiliation

• University of Washington Schools of Dentistry,
  Medicine and Public Health
• Departments of Dental Public Health Sciences,
  Pediatrics, Health Services, Pediatric Dentistry

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Background

• Rates of early childhood caries 4.5 fold higher
  among Alaska Natives
• High rates of caries likely related to
• high load of oral bacteria that cause caries
• S. mutans, S. sobrinus
• early acquisition
• decreased fluoride exposure
• large amounts of refined sugar in diet
• poor oral hygiene

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Specific Aim

• To determine if the infants of pregnant mothers
  who use CHX mouth rinses for two weeks, followed
  by xylitol gum use for two years, experience less
  dental decay compared to infants of mothers who
  do not use these interventions

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Methods Design

• Randomized controlled trial
• 2 arms intervention vs. control
• double-blinded

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Yukon-Kuskokwim Delta
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Subjects

• Enroll Pregnant mothers at 36-38
  weeks of gestation
• Track outcomes
• Mothers
• Liveborn children who are offspring of enrollees
• Exclude infants born in Anchorage, infants with
  congenital anomalies

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Intervention Both Groups

• Dental hygiene and exam
• Restoration of caries and extractions as
  necessary
• Dental and dietary counseling/education
• Toothbrushes and toothpaste

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Intervention Group Only

• Chlorhexidine rinses, twice a day for two weeks
  starts at enrollment
• Xylitol gum 5.1 grams per day (3x/day) for two
  years

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Outcome Assessment

• Outcomes of interest
• caries among infants at 1 and 2 years of age
• all enrolled children
• deft
• S. mutans counts for mothers and infants at same
  time intervals
• for subset (n30) only

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Data Collection

• Baseline
• maternal dental exam
• maternal gingival culture (subset)
• maternal oral health questionnaire
• T1 (infant age one year)
• oral health questionnaire
• infant dental exam
• infant and maternal gingival cultures (subset)

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Data Collection

• T2 (infant age2 years)
• oral health questionnaire
• infant dental exam
• infant and maternal gingival cultures (subset)

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Analysis

• Compare rates of caries between intervention and
  control groups
• (unit of analysis child or teeth)
• Compare S. mutans counts between groups
• Control for confounding factors, if present

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Potential limitations

• Compliance with intervention
• Blinding
• Misclassification of exposure
• e.g. control mom uses intervention
• mother doesnt rear child
• Intensification of exposure
• e.g. whole family uses gum

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Sample Size Estimates

• N375 births/year
• Exclude 25 born in Anchorage
• Assume 10 refusal rate
• Enroll approximately 125 in each group
• Assume 80 follow-up at two years
• Need about 200 at final follow-up
• About 90 power to detect a 50 reduction in the
  intervention group

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Future studies
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Xylitol administration with a slow-release
pacifier for AOM and ECC?
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Diet and dental caries
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Subsidizing toothpaste, introducing xylitol snacks
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What is most impressive about xylitol is its
safety
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Effectively addressing caries will require new
and better tools for public health
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THANK YOU